Design principles that are based upon the concepts of crystal engineering and self-assembly have recently afforded new classes of crystalline solids that possess important physical properties such as bulk magnetism or porosity. Large-scale molecular networks have been developed to encapsulate other materials and these are playing an ever-increasing role in the pharmaceutical industry and as materials for sensors, and liquid crystals. In addition, with the inclusion of metals within the structures, the large polymers formed by these crystals have magnetic properties as well as exhibiting catalytic properties.
In recent years, chemists have developed synthetic design strategies that are based on the concept of self-assembly. This supramolecular approach to synthesis has afforded a new generation of discrete, high molecular weight compounds. These compounds are exemplified by nanoscale spheroid architectures that are based upon Platonic, or regular, and Archimedean, or semi-regular, solids. Nanoscale versions of Platonic and Archimedean solids have been prepared wherein their building blocks, molecular polygons, are connected at their edges. Closed convex polyhedra are generated in this manner.
In contrast to the Platonic and Archimedean solids that have been generated by edge-sharing of molecular polygons, it would be advantageous to produce open-shell polyhedra, which would necessarily be porous in a predictable manner, and thus be susceptible to a high degree of control over structure and functionality.